Random access resource allocation for integrated access and backhaul nodes

ABSTRACT

A wireless communication method includes configuring, by a first communication node, a first set of parameters related to random access procedure by a second communication node on a first communication link between the first communication node and the second communication node, and receiving, from the second communication node, a random access signal that uses the first set of parameters on the first communication link. The first communication node also provides wireless connectivity to a third communication node via a second communication link that shares at least some transmission resources with the first communication link. The first set of parameters includes one or more of a random access format, a random access sequence index set, a random access sequence root sequence index, a random access cyclic shift, and random access time-frequency resources.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of priority under 35 U.S.C. § 120 asa continuation of U.S. Non-provisional application Ser. No. 17/108974,filed on Dec. 1, 2020, which claims the benefit of priority under 35U.S.C. § 120 as a continuation of PCT Patent Application No.PCT/CN2018/095064, filed on Jul. 10, 2018, the disclosure of which isincorporated herein by reference in its entirety.

TECHNICAL FIELD

This document relates to systems, devices and techniques for wirelesscommunications.

BACKGROUND

Efforts are currently underway to define next generation wirelesscommunication networks that provide greater deployment flexibility,support for a multitude of devices and services and differenttechnologies for efficient bandwidth utilization. The next generationwireless communication networks are also expected to deploy new corenetworks that provide additional services and flexibility beyondcurrently available core networks.

SUMMARY

This document describes technologies that can be used by network devicesto allocate random access resources to a class of wireless devices suchas the integrated access and backhaul (IAB) node.

In one example aspect, a method of wireless communication is disclosed.The method includes configuring, by a first communication node, a firstset of parameters related to random access procedure by a secondcommunication node on a first communication link between the firstcommunication node and the second communication node, and receiving,from the second communication node, a random access signal that uses thefirst set of parameters on the first communication link. The firstcommunication node also provides wireless connectivity to a thirdcommunication node via a second communication link that shares at leastsome transmission resources with the first communication link. The firstset of parameters includes one or more of a random access format, arandom access sequence index set, a random access sequence root sequenceindex, a random access cyclic shift, and random access time-frequencyresources.

In another example aspect, another method of wireless communication isdisclosed. The method includes, receiving, from a first communicationnode, a first set of parameters related to random access procedure by asecond communication node on a first communication link between thefirst communication node and the second communication node, andtransmitting, from the second communication node, a random access signalthat uses the first set of parameters on the first communication link,wherein the first communication node also provides wireless connectivityto a third communication node via a second communication link thatshares at least some transmission resources with the first communicationlink, wherein the first set of parameters includes one or more of arandom access format, a random access sequence index set, a randomaccess sequence root sequence index, a random access cyclic shift, andrandom access time-frequency resources.

In yet another example aspect, a wireless communications apparatuscomprising a processor is disclosed. The processor is configured toimplement methods described herein.

In another example aspect, the various techniques described herein maybe embodied as processor-executable code and stored on acomputer-readable program medium.

The details of one or more implementations are set forth in theaccompanying drawings, and the description below. Other features will beapparent from the description and drawings, and from the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an example of a wireless system in which IAB nodes aredeployed.

FIG. 2 shows an example of physical random access channel (PRACH)formats using B4, A1 and C2 random access formats.

FIG. 3 shows an example implementation in which a collision of randomaccess transmissions may occur.

FIG. 4 is a flowchart of an example wireless communication method.

FIG. 5 is a flowchart of an example wireless communication method.

FIG. 6 is a block diagram example of a wireless communication apparatus.

Like reference symbols in the various drawings indicate like elements.

DETAILED DESCRIPTION

The present document relates to the field of wireless communicationsand, in particular, to a method and an apparatus for allocating randomaccess resources of an IAB node in a mobile communication system.

Section headings are used in this document to facilitate readability anddo not limit the embodiments and techniques described in each section tothat section only. Accordingly, embodiments may use together with eachother techniques described in different sections.

To make the objectives, technical solutions, and advantages of thepresent invention clearer, the following describes the embodiments ofthe present invention in detail with reference to the accompanyingdrawings. It should be noted that, in the case of no conflict, theembodiments in the present application and the features in theembodiments can be combined with each other arbitrarily.

Brief Discussion

The new generation of mobile communication system NR (new radio) allowsmore flexible network networking modes than the 2G, 3G, and 4G systemsand the existence of new types of network nodes. Currently integratedIBA Nodes (Integrated Access and Backhaul Node) integrating a backhaullink and a normal NR access link can provide more flexible coverage andnetworking than a single cellular coverage. The method will be animportant part of the future mobile communications network.

For a new generation of mobile communication systems using IAB nodes,IAB nodes can be regarded as ordinary terminals as well as base stationsaccessed by other terminals, as shown in FIG. 1 : IAB Node and IAB Donorfor communication, the communication link is a backhaul link. In thiscase, the IAB Node1 can be regarded as an ordinary terminal; but the IABNode1 can also communicate with other common terminal UEs in group A(Group A) and other IAB Node2, and the communication link is an accesslink from IAB Node1 aspect. This time, this IAB Node1 can be regarded asa special kind of base station. It becomes the relay between otherordinary terminals and other IAB Nodes with IAB donors. The special partlies in the fact that the IAB Node is a special type of integration ofbase station and terminal. Its deployment location is very differentfrom that of ordinary terminals. For example, IAB Nodes are often fixedbelow the eaves, and they are much higher than ordinary terminals, thisis easy for IAB Donor establishing a direct radio path to IAB Nodes; forexample, the IAB Node often has more antennas ports than the normalterminal; also, for example, the IAB Node may need to be placed fartheraway from the IAB donor than the normal terminal (such as the IAB Node3in the FIG. 1 ) coverage of ordinary terminals, etc. These differentpoints put different demands on the transmission of random accessbetween the IAB Node and the IAB donor. It is necessary to consider thearrangement and configuration of the IAB Node's random access resourcesand formats in a targeted manner.

Examples of Base Station Side Techniques

Example A1. The IAB anchor or IAB parent node configures a random accessparameter for the IAB node. After the configuration, the IAB anchor orIAB parent node receives the random access signal sent by the IAB nodeon the backhaul link. The random access parameters include one or anycombination of a random access format, a random access sequence indexset, a random access sequence root sequence index, a random accesscyclic shift, and random access time-frequency resources.

Example A2. The operation in Example A1, wherein the random accessformat of the random access parameters configured for the IAB node isindependently configured from the random access format for the non-IABnode. For example, the independent configuration may mean that anyrandom access parameter is possible for a given random access format. Inother words, given value of one of the random access format or randomaccess parameter, the value of the other may be indeterminable.

Example A3. The operation of Example A1, wherein the random accesssequence index set in the random access parameter configured for the IABnode and the random access index set for non-IAB nodes are configured byan independent configuration.

Example A4. The operation of Example A1, wherein: the random access rootsequence index in the random access parameter for the IAB node and therandom access root sequence index for non-IAB nodes are configured by anindependent configuration. Furthermore, the random access cyclic shiftfor the IAB node and the random access cyclic shift for non-IAB nodesare configured by an independent configuration.

Example A5. The operation of Example A1, wherein: the random accesstime-frequency domain resources for IAB node and random accesstime-frequency domain resources for non-IAB nodes are independentlyconfigured. For example, the two types of random access time-frequencyresources may not overlap or overlap partially.

Examples of Terminal Side Techniques

Example B1: A method for allocating random access resources in which IABnode receives IAB node random access parameters. Based on the receivedIAB node random access parameters, the IAB node sends a random accesssequence for a backhaul link according to the IAB node random accessparameter. The IAB node may also receive a random access signal for anaccess link sent by an IAB terminal. The random access parametersinclude random access format, random access sequence index set, randomaccess sequence root sequence index, random access cyclic shift, one orany combination of random access time-frequency resources.

Example B2. The operation of Example B1, wherein the random accessformat of the IAB node random access parameter and the random accessformat of a non-IAB node are independently configured. For example, theindependent configuration may mean that any random access parameter ispossible for a given random access format. In other words, given valueof one of the random access format or random access parameter, the valueof the other may be indeterminable.

Example B3. The operation of Example B1, wherein the random accesssequence index set in the IAB node random access parameter isindependently configured from the random access index set of non-IABnodes.

Example B4. The operation of Example B1, wherein: the random access rootsequence index and cyclic shift in the IAB node random access parameter,and the random access root sequence index and cyclic shift in thenon-IAB node random access parameter are independently configured.

Example B5. The operation of Example B1, characterized in that therandom access time-frequency resources in the IAB node random accessparameters and the random access time-frequency resources in the non-IABnode random access parameters are independently configured. The twotypes of random access time-frequency resources may not overlap oroverlap partially.

Example B6. The operation of Example B1, wherein: the IAB nodeconfigures the random access parameter of the random access signal forthe access link to the IAB terminal.

Example B7. The operation of Example B6, wherein the parameters of therandom access configured by the IAB node to the IAB terminal arereported by the IAB node to the IAB donor or the IAB parent node.

Example Embodiments

When the IAB node is deployed in the next generation of mobilecommunication network, the IAB node deployment location and themulti-antenna characteristic of the IAB node itself cause the randomaccess format selection of the IAB node to be different from that of anordinary terminal such as user equipment (UE). The random access formatselection needs to match the coverage of different distances, differentRF transmission environments, and the additional path loss values thatneed to be compensated. The IAB nodes generally have higher heights, andoften have more direct radio paths with other network nodes such as abase station. This is in contrast to the lower height of ordinaryterminals, which leads to significantly different propagationenvironments in urban areas where the radio path is mostly indirect. Forexample, most user devices may be operated within 6 feet of ground,where many other interfering objects such as cars, buildings and treesare found. On the other hand, IAB devices may often be deployed nearroof tops, and may be operating at heights of 20 to 30 feet or above,thus avoiding many interferers or reflectors experienced by userdevices.

In general, because an ordinary terminal is mainly in an indirect pathscenario, the path loss value that needs to be compensated is alsorelatively high. This scenario may force the wireless system to use therandom access format B4 or longer format. The random access format B4has a large number of short sequences (12, to be precise). More shortsequences are accumulated to achieve energy gain to compensate forhigher path loss. However, since the guard time of the prefix and suffixof the B4 format is shorter than that of the random access format C2,under the scenario that the coverage distance is determined only by theround-trip time of the electromagnetic signal between the base stationand the terminal, the effective coverage of a B4 transmission extendsover an area that is less than that of C2. That is to say, the format C2is suitable for the scenario that the coverage is wider than the normalterminal and is based on the direct radio path.

In addition, typically, an IAB node has more antennas than a typical UE.Therefore, path loss is not the main transmission obstacle that the IABnode needs to overcome when sending a random access signal. The randomaccess format C2 has a long enough prefix and guard time suffix toresist large time delays due to propagation delay. Therefore, IAB nodesmay prefer to use C2 format random access signals over another formatsuch as the B4 random access format.

FIG. 2 shows the random access format B4, A1 and C2 signal structure.

Table 1 shows examples of parameters of random access formats B4, C2,and A1. The column headers use the following abbreviations: CP For thecyclic prefix, GP is the guard time, Ts is the sampling point.

TABLE 1 Random Sequence CP length Total sequence GP length Access Formatnumber (Ts) length (Ts) (Ts) B4 12 936 24576 792 C2 4 2048 8192 2912 A12 288 4096 0

However, in the existing draft standards of new generation communicationsystems, only one random access signal format is allowed to be allocatedin the same BWP (bandwidth part), and it is not allowed tosimultaneously configure the formats B4 and C2. Because if the formatsB4 and C2 are configured at the same time, since the prefix lengths ofthe two formats are different, the relative starting points of theeffective short sequence symbols are different, which may causeambiguity in the timing determination. In addition, because the numberof short sequence symbols supported by the two formats is different,random access preamble signals cannot be blindly detected in a longerformat, which may cause access failure. Therefore, when two or morerandom access signal formats are possible for a same bandwidth part(BWP), the type of the random access signal format actually being usedby a transmission can be effectively distinguished at the base stationside using techniques described herein. The following four examplesillustrate the related solutions.

Embodiment Example 1 Resource Allocation Scheme for Random AccessSignals of IAB Nodes in Normal Coverage

As shown in FIG. 1 , the IAB Node 1 is within the normal coverage of theIAB donor. The normal coverage refers to the maximum coverage that anordinary terminal that is not an IAB node can support. In the normalcoverage, code division, specifically, the specific index of the IABnode within the range of the random access preamble index can be used todistinguish from the normal terminal. In general, BWP in thenext-generation mobile communication system supports the terminal torandomly select among 64 random access preambles. In addition to this,some embodiments may follow a rule that some of the 64 random preambleindexes are dedicated to the IAB node, and the base station can identifywhether a received random access preamble sequence was sent by the IABnode or by the non-IAB node by identifying the index of the receivedrandom access preamble from all possible preambles (e.g., 64 preambles),and then checking whether the index was from dedicated portion or fromthe non-dedicated portion of the random access indexes.

Embodiment Example 2 Resource Allocation Scheme for Random AccessSignals of IAB Nodes Outside Normal Coverage

As shown in FIG. 1 , the IAB Node3 is outside the normal coverage of theIAB donor. Here, the “normal” coverage may refer to a nominal range ofcoverage for which the corresponding base station that is the IAB donor.Due to the difference in coverage with ordinary terminals, e.g.,different physical layer characteristics of the wireless channel betweenthe IAB donor and the IAB node, in some embodiments, the IAB nodes mayuse different random access preamble formats to meet the need forenhanced coverage, such as using the format C2 that is specifically usedfor coverage enhancement.

The set of random access preamble sequences for the next generationmobile communication system may be obtained by cyclically shifting aroot sequence multiple times. If all cyclic shifts under the same rootsequence do not satisfy the 64 indexes in BWP, embodiments should usemore root sequences to generate more random access sequence indexesuntil a total of 64 indexes are generated. The size of the cyclic shift(Ncs) determines the number of sequences that can be generated under asingle root sequence. The larger the Ncs is, the fewer the sequencesthat can be generated, and vice versa. Since the value of Ncs shouldmeet the requirement of the zero correlation window, its value dependson the size of the coverage area of the cell. The larger the coveragearea of the cell, the larger the value of Ncs should be, and the smallerthe coverage area, smaller the value of Ncs is. Since the coverage ofIAB Node3 is larger than that of normal terminals, the Ncs_IAB of IABNode3 should be larger than the cyclic shift Ncs_UE of random accesssequences of normal terminals or UEs.

In the case where Ncs is different, the IAB node's root sequence of therandom access preamble sequence should not be the same as the randomaccess root sequence of an ordinary terminal. Furthermore, its rootsequence should be independent of the random access root sequence of anordinary terminal. In addition to the normal terminal's random accessroot sequence and Ncs, the system also should configure an independentrandom access root sequence and Ncs_IAB for IAB nodes. The IAB-specificroot sequence and Ncs_IAB determine the set of random access sequencesavailable for IAB nodes.

Embodiment Example 3 Conflict Resolution of Random Access SignalsBetween an IAB Node and an Ordinary Terminal

Compared with ordinary terminals (e.g., UEs), IAB nodes have a smallerdensity in the network deployments, and therefore require fewer randomaccess resources. Thus, a random access time-frequency resourcearrangement for IAB nodes could be sparser than for ordinary UEs. Evenso, there is always a possibility of occurrence of collision of randomaccess transmissions initiated between the two (IAB node and UE), andthus cannot fundamentally avoid the problem that the random accesssequence transmitted by the ordinary terminal and the IAB node collideson the same time-frequency resource. Although from the perspective ofthe IAB donor node, when the random access sequences sent by theordinary terminal and the IAB node collides on the same time-frequencyresource, it may be possible to determine whether the detected randomaccess sequence is an IAB-dedicated random access preamble sequence. Themapping relationship between the random access resource of the IAB nodeand the downlink signal and the mapping relationship between the normalterminal random access resource and the downlink signal are not thesame, and when in the same time-frequency resource being used for signaltransmission, if transmissions with two random access formats thatcollide with each other, the best receiving beam cannot simply be takeninto consideration at the receiving side of the base station, whichgreatly increases the probability of detection failure.

FIG. 3 illustrates an example of collision between the receive beams ofthe IAB random access and random access of ordinary users. As shown inFIG. 3 , the ordinary terminal uses the B4 format. There is only onerandom access sequence 1 that can fit within a time slot. In this case,the mapped downlink signal is a sync block 1 (SSB 1). In thisconfiguration, an IAB node uses a C2 format. Since C2 is shorter thanB4, it is possible to have two consecutive random access sequences 2 and3 in the time slot, and the corresponding mapped sync blocks are 2 and3. The base station may use either receive beam 1 corresponding to syncblock 1 or receive beams 2 and 3 corresponding to sync blocks 2 and 3 atthis random access opportunity (RO: RACH occasion). If the base stationuses beam1, this is not the best beam for sequences 2 and 3, and if thebase station uses beam2 and beam3, these are not the best beams forsequence 1. A single best beam cannot fit for all situations.

Therefore, one way to solve the conflict problem is still to configurethe random access time-frequency resources of IAB nodes and the randomaccess time-frequency resources of ordinary terminals independently, andto ensure that there is no overlap between them. The sub-optimal methodis the independent configuration of both time-frequency resources, butallows a certain percentage of overlap. If it is indeed because ofresource limitation, the random access time-frequency resources of theIAB node and the ordinary terminal cannot be configured independently,then it is beneficial to ensure that the downlink signals mapped by thecorresponding random access occasions on the same time-frequencyresource are consistent.

Still taking FIG. 3 as an example, an ordinary terminal uses the B4format. There is only one random access sequence 1 in a time slot. Themapped downlink signal is a sync block 1, the IAB node uses a C2 format,and there are two random access sequence in one time slot. Thesuccessive random access sequences 2 and 3 must also have a mapped syncblock of 1. This particular mapping relationship guarantees that it isnot difficult to implement because the ratio of the number of availableB4 and C2 in a time slot is determined, and the mapping relationshipbetween the downlink signal and the random access occasion can be setaccording to this ratio. For example, if the mapping relationshipbetween the downlink signal and the random access opportunity is set to1:1 for the B4 format, the mapping relationship between the downlinksignal and the random access opportunity configured in the C2 format is1:2.

Embodiment Example 4 Conflict Resolution of Random Access Signals of IABNodes and IAB Terminals

The IAB node is a hybrid of a network node and a terminal. The nodeitself has an independent cell identifier (Cell ID) and independentradio resource management capability. The IAB node can configure randomaccess parameters that are independent of ordinary terminals for IABterminals within the coverage of the IAB node. Since the conventionalcoverage controlled by IAB nodes is much smaller than that of theordinary anchor base station, and the multi-antenna capability of IAB isalso different from that of anchor base stations, it is also useful toconfigure the IAB terminals within the coverage of IAB nodes to beindependent of ordinary terminal's random access parameters. Forexample, the random access format A1 is configured for the IAB terminalthat within the coverage of the IAB node, and the random access formatof the terminal under the control of the anchor node or the IAB parentnode base station is B4, and the total length of the random accessformat A1 sequence is shorter. This makes the format suitable for a cellwith a very smaller coverage and also facilitates control ofinterference to random access signals sent by ordinary terminals. TheIAB node should therefore configure the IAB terminal with a randomaccess root sequence and Ncs independent of the normal terminal and theIAB node.

The parameters of the random access procedure, configured by the IABnode to the IAB terminal, may also be reported to the IAB donor or theIAB parent node. Reporting the corresponding random access resourceparameter is beneficial to the IAB donor or the IAB parent node toproperly configure the RACH resources of the IAB node and the IAB nodeto receive the downlink backhaul link resources according to the RACHresources of the IAB terminal so as to avoid the collision with RACHaccess link of the IAB terminal. Resolving resource conflicts on theaccess link is especially important when the IAB uses wavelengthdivision multiplexing to isolate return links and access links.

FIG. 4 is a flowchart depiction of a method 400 of wirelesscommunication. The method 400 includes configuring (402), by a firstcommunication node, a first set of parameters related to random accessprocedure by a second communication node on a first communication linkbetween the first communication node and the second communication node,and receiving (404), from the second communication node, a random accesssignal that uses the first set of parameters on the first communicationlink. The first communication node also provides wireless connectivityto a third communication node via a second communication link thatshares at least some transmission resources with the first communicationlink. The first set of parameters includes one or more of a randomaccess format, a random access sequence index set, a random accesssequence root sequence index, a random access cyclic shift, and randomaccess time-frequency resources.

FIG. 5 is a flowchart depiction of an example method 500 of wirelesscommunication. The method 500 includes, receiving (502), from a firstcommunication node, a first set of parameters related to random accessprocedure by a second communication node on a first communication linkbetween the first communication node and the second communication node,and transmitting (504), from the second communication node, a randomaccess signal that uses the first set of parameters on the firstcommunication link. The first communication node also provides wirelessconnectivity to a third communication node via a second communicationlink that shares at least some transmission resources with the firstcommunication link. The first set of parameters includes one or more ofa random access format, a random access sequence index set, a randomaccess sequence root sequence index, a random access cyclic shift, andrandom access time-frequency resources.

With reference to methods 400 and 500, in some embodiments, the firstcommunication node may be an IAB parent node (e.g., a base station oranother network node). In such a case, the second communication node maybe an IAB node and the first communication link may be a backhaul link.In some embodiments, the first communication node, e.g., the IAB parentnode, may also be configured to provide wireless connectivity to a thirdcommunication node such as a user device or UE. In such a case, thecommunication link between the first and third communication nodes maybe the wireless channel to/from the user device and from/to the basestation.

With reference to methods 400 and 500, in some embodiments, theconfiguration of the random access format in the first set of parametersis not related to the random access format in the second set ofparameters used by the third node for random access using the secondcommunication link, and therefore these parameters may be independentlyassigned.

As described, several of the parameters associated with random accesschannel procedure may be used during methods 400 and 500. Theseparameters may include random access format, a random access sequenceindex set, a random access sequence root sequence index, a random accesscyclic shift, and random access time-frequency resources. Furthermore,these parameters may be independently assigned on the first and secondcommunication links. For example, these assignments may be based on theconditions of each communication link, and decision taken regardingwhich parameter to select for use on one link may not have any influenceon the decision taken for the other link. In some embodiments, thesecond communication node (e.g, an IAB node) may provide wirelessconnectivity to another network node. This another network node may bean IAB node or may be a UE.

FIG. 6 shows an example of a wireless communication apparatus 600. Theapparatus 600 may implement the methods 400 or 500 or other techniquesdescribed in the present document. The apparatus 600 may be, forexample, the first communication node, the second communication node, orthe third communication node described herein. For example, theapparatus 600 may implement functionality of a base station (e.g., eNBor gNB). In some embodiments, the apparatus 600 may be used to implementa user device such as a smartphone, an IoT device, a laptop, a tablet,and so on.

The apparatus 600 includes one or more processor 610. The apparatus 600may include one or more memories 620. The apparatus 600 may include oneor more transmitters 630. The apparatus 600 may include one or morereceivers 640. The processor 610 may be configured to execute code andimplement a wireless communication method such as method 400 or method500. The memory 620 may be used to store processor-executable code,data, results of intermediate calculations during the execution ofwireless communication methods, and so on. The transmitter 630 may beconfigured to transmit, via a network interface, at least some of thevarious messages and signals described herein. The receiver 640 may beconfigured to receive, via a network interface, at least some of thesignals and messages described herein. The apparatus 600 may usemultiple transmitters and or receivers, for example, for performingcommunication on a cellular wireless and a backhaul connection.

The disclosed and other embodiments, modules and the functionaloperations described in this document can be implemented in digitalelectronic circuitry, or in computer software, firmware, or hardware,including the structures disclosed in this document and their structuralequivalents, or in combinations of one or more of them. The disclosedand other embodiments can be implemented as one or more computer programproducts, i.e., one or more modules of computer program instructionsencoded on a computer readable medium for execution by, or to controlthe operation of, data processing apparatus. The computer readablemedium can be a machine-readable storage device, a machine-readablestorage substrate, a memory device, a composition of matter effecting amachine-readable propagated signal, or a combination of one or morethem. The term “data processing apparatus” encompasses all apparatus,devices, and machines for processing data, including by way of example aprogrammable processor, a computer, or multiple processors or computers.The apparatus can include, in addition to hardware, code that creates anexecution environment for the computer program in question, e.g., codethat constitutes processor firmware, a protocol stack, a databasemanagement system, an operating system, or a combination of one or moreof them. A propagated signal is an artificially generated signal, e.g.,a machine-generated electrical, optical, or electromagnetic signal, thatis generated to encode information for transmission to suitable receiverapparatus.

A computer program (also known as a program, software, softwareapplication, script, or code) can be written in any form of programminglanguage, including compiled or interpreted languages, and it can bedeployed in any form, including as a standalone program or as a module,component, subroutine, or other unit suitable for use in a computingenvironment. A computer program does not necessarily correspond to afile in a file system. A program can be stored in a portion of a filethat holds other programs or data (e.g., one or more scripts stored in amarkup language document), in a single file dedicated to the program inquestion, or in multiple coordinated files (e.g., files that store oneor more modules, sub programs, or portions of code). A computer programcan be deployed to be executed on one computer or on multiple computersthat are located at one site or distributed across multiple sites andinterconnected by a communication network.

The processes and logic flows described in this document can beperformed by one or more programmable processors executing one or morecomputer programs to perform functions by operating on input data andgenerating output. The processes and logic flows can also be performedby, and apparatus can also be implemented as, special purpose logiccircuitry, e.g., an FPGA (field programmable gate array) or an ASIC(application specific integrated circuit).

Processors suitable for the execution of a computer program include, byway of example, both general and special purpose microprocessors, andany one or more processors of any kind of digital computer. Generally, aprocessor will receive instructions and data from a read only memory ora random access memory or both. The essential elements of a computer area processor for performing instructions and one or more memory devicesfor storing instructions and data. Generally, a computer will alsoinclude, or be operatively coupled to receive data from or transfer datato, or both, one or more mass storage devices for storing data, e.g.,magnetic, magneto optical disks, or optical disks. However, a computerneed not have such devices. Computer readable media suitable for storingcomputer program instructions and data include all forms of non-volatilememory, media and memory devices, including by way of examplesemiconductor memory devices, e.g., EPROM, EEPROM, and flash memorydevices; magnetic disks, e.g., internal hard disks or removable disks;magneto optical disks; and CD ROM and DVD-ROM disks. The processor andthe memory can be supplemented by, or incorporated in, special purposelogic circuitry.

While this document contains many specifics, these should not beconstrued as limitations on the scope of an invention that is claimed orof what may be claimed, but rather as descriptions of features specificto particular embodiments. Certain features that are described in thisdocument in the context of separate embodiments can also be implementedin combination in a single embodiment. Conversely, various features thatare described in the context of a single embodiment can also beimplemented in multiple embodiments separately or in any suitablesub-combination. Moreover, although features may be described above asacting in certain combinations and even initially claimed as such, oneor more features from a claimed combination can in some cases be excisedfrom the combination, and the claimed combination may be directed to asub-combination or a variation of a sub-combination. Similarly, whileoperations are depicted in the drawings in a particular order, thisshould not be understood as requiring that such operations be performedin the particular order shown or in sequential order, or that allillustrated operations be performed, to achieve desirable results.

Only a few examples and implementations are disclosed. Variations,modifications, and enhancements to the described examples andimplementations and other implementations can be made based on what isdisclosed.

We claim:
 1. A method for wireless communications, comprising:configuring, by a first communication node, a first set of parametersrelated to random access procedure by a second communication node on afirst communication link between the first communication node and thesecond communication node; and receiving, from the second communicationnode, a random access signal that uses the first set of parameters onthe first communication link; wherein the first communication nodeprovides wireless connectivity to a third communication node via asecond communication link that shares at least some transmissionresources with the first communication link; and wherein the first setof parameters includes one or more of a random access format, a randomaccess sequence index set, a random access sequence root sequence index,a random access cyclic shift, and random access time-frequencyresources.
 2. The method of claim 1, wherein the first communicationnode configures the random access format in the first set of parametersindependent from the random access format in a second set of parametersused by the third communication node for random access using the secondcommunication link.
 3. The method of claim 1, wherein the firstcommunication nodes configures the random access sequence index set inthe first set of parameters independently from a random access sequenceindex set in the second set of parameters.
 4. The method of claim 1,wherein the first communication node configured the random access rootsequence index and random access cyclic shift in the first set ofparameters independently from a random access root sequence index andrandom access cyclic shift in the second set of parameters.
 5. Themethod of claim 1, wherein the first communication node independentlyconfigures the random access sequence root sequence index for the firstcommunication link and the second communication link.
 6. The method ofclaim 1, wherein the first communication node independently configurestransmissions resources for random access transmissions for the secondcommunication node and third communication node.
 7. The method of claim6, wherein the transmission resources include time or frequencyresources, and wherein transmission resources for the secondcommunication node and transmission resources for the thirdcommunication node are partially overlapping.
 8. A method of wirelesscommunication, comprising: receiving, from a first communication node, afirst set of parameters related to random access procedure by a secondcommunication node on a first communication link between the firstcommunication node and the second communication node; and transmitting,from the second communication node, a random access signal that uses thefirst set of parameters on the first communication link; wherein thefirst communication node provides wireless connectivity to a thirdcommunication node via a second communication link that shares at leastsome transmission resources with the first communication link; andwherein the first set of parameters includes one or more of a randomaccess format, a random access sequence index set, a random accesssequence root sequence index, a random access cyclic shift, and randomaccess time-frequency resources.
 9. The method of claim 8, wherein thefirst communication node configures the random access format in thefirst set of parameters independent from the random access format in asecond set of parameters used by the third communication node for randomaccess using the second communication link.
 10. The method of claim 8,wherein the first communication nodes configures the random accesssequence index set in the first set of parameters independently from arandom access sequence index set in the second set of parameters. 11.The method of claim 9, wherein the first communication node configuredthe random access root sequence index and the random access cyclic shiftin the first set of parameters independently from a random access rootsequence index and random access cyclic shift in the second set ofparameters.
 12. The method of claim 8, wherein the first communicationnode independently configures the random access sequence root sequenceindex for the first communication link and the second communicationlink.
 13. The method of claim 8, wherein the first communication nodeindependently configures transmissions resources for random accesstransmissions for the second communication node and the thirdcommunication node.
 14. The method of claim 13, wherein the transmissionresources include time or frequency resources, and wherein transmissionresources for the second communication node and transmission resourcesfor the third communication node are partially overlapping.
 15. Themethod of claim 8, further including, configuring, by the secondcommunication node, random access parameters for another network node towhich the second communication node provides wireless connectivity. 16.The method of claim 15, further including reporting by the secondcommunication node to the first communication node, the random accessparameters for the another network node.
 17. A first communication nodecomprising at least one processor configured to: configure a first setof parameters related to random access procedure by a secondcommunication node on a first communication link between the firstcommunication node and the second communication node; receive, from thesecond communication node, a random access signal that uses the firstset of parameters on the first communication link; and provide wirelessconnectivity to a third communication node via a second communicationlink that shares at least some transmission resources with the firstcommunication link, wherein the first set of parameters includes one ormore of a random access format, a random access sequence index set, arandom access sequence root sequence index, a random access cyclicshift, and random access time-frequency resources.
 18. The firstcommunication node of claim 18, the at least one processor furtherconfigured to: configure the random access format in the first set ofparameters independent from the random access format in a second set ofparameters used by the third communication node for random access usingthe second communication link.
 19. A second communication nodecomprising at least one processor configured to: receive, from a firstcommunication node, a first set of parameters related to random accessprocedure by a second communication node on a first communication linkbetween the first communication node and the second communication node;and transmit a random access signal that uses the first set ofparameters on the first communication link; wherein the firstcommunication node provides wireless connectivity to a thirdcommunication node via a second communication link that shares at leastsome transmission resources with the first communication link; andwherein the first set of parameters includes one or more of a randomaccess format, a random access sequence index set, a random accesssequence root sequence index, a random access cyclic shift, and randomaccess time-frequency resources.
 20. The second communication node ofclaim 19, wherein the first communication node configures the randomaccess format in the first set of parameters independent from the randomaccess format in a second set of parameters used by the thirdcommunication node for random access using the second communicationlink.